[41.04] Properties of the Highly Ionized High-Velocity Absorption Systems in the UV Spectra of four AGNs

We present a detailed ultraviolet absorption line study of
four high-positive-velocity, highly ionized systems toward
the active galaxies HE 0226-4110, Mrk 509, PG 0953+414, and
PKS 0405-12. Using Far-Ultraviolet Spectroscopic Explorer
(FUSE) and Hubble Space Telescope Imaging Spectrograph
(HST/STIS) observations, we explore the kinematics and
physical conditions in the highly ionized absorbers with
velocities ranging from 100 to 300 km s-1, in an
attempt to understand their origins. The inter-relationships
between the properties of absorption in different ionic
species (e.g. H I, C III, C IV, Si III, Si IV, and O VI)
reveal a wealth of information about the absorbing gas. It
has been claimed that the high-velocity O VI detections
trace gas in the Local Group, possibly as part of a warm-hot
extragalactic filament. We consider whether the
high-velocity O VI in our sight lines is distant
extragalactic material, or might instead be tracing either a
fountain outflow or matter that has been tidally stripped
from nearby dwarf galaxies. We appreciate financial support
from NASA contract NAS5-32985.